Conventionally, in manufacturing fuel rods of the type used in nuclear reactors, hollow stainless steel, zircaloy or other material tubing is filled with cylindrical fuel pellets and capped on both ends with plugs which temporarily are attached to the tubing by a force fit. These plugs are then permanently sealed in position with a tungsten inert weld by rotating the tubing relative to an electrode which forms a girth weld at the tubing-plug interface. Since the tubing is charged with high pressure helium through an orifice in one end plug, a second welding operation is then carried out to seal the plug orifice.
This second operation of sealing the orifice is a costly process since a special weld chamber sufficiently strong to accommodate high pressure gas and of gas tight integrity is necessary to contain the pressurization gas without leakage. Further, in addition to requiring a separate welding machine and operation, the orifice weld must be inspected by X-ray techniques to assure that gas charged in the fuel rod will not thereafter leak when the fuel rod undergoes a fission process in a nuclear reactor.